/**
 * @file   hello.cpp
 * @author harrior Zhang <2725110762@qq.com>
 * @date   Tue Sep 21 11:51:03 2021
 * 
 * @brief  
 * 
 * 
 */


#include <iostream>

/**
 * main function.
 * @param argc number of shell parameters.
 * @argv strings for all parameters.
 * 
 * @return system signals.
 * 
 * 
 */

int main(int argc, char* argv[])
{
  /// Just a demo.
  std::cout << "Hello world!\n" << std::endl;
  return 0;
}
